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Hi,
I want to develop a simple POS machine software for a supermarket.. It seems that everything is fine but I just want to know how can I open the cash drawer from my C# application regardless of the machine brand and model?
Thanks,
Jassim Rahma
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Again I must tell you to stop flooding forum with question only from your side.
kindly follow my suggestion what I gave you on ASP.NET forum, Please.
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if your subject line is any good, then typing it into either the Google search bar, or the CodeProject search bar, would yield the answer you want. Now start learning to search.
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You can't. Any question of the format "how can I <do some hardware function> from my C# application regardless of the machine brand and model" will have the same answer. In situations like that you code for the most popular hardware configurations. How many hardware types you include depends on the market segmentation of the hardware. In other words if 2 vendors cover 80% of the market, 2 is enough, but if to get 50% market penetration you need to cover 4 vendors, you might want to go 5 or 6. Then if you have built a product that is useful enough someone may pay you to add in other hardware platforms.
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Hi,
I have below problem.
An XSD schema file is converted into a C# class via XSD.exe.
Object of the C# class is stored into an object pool.
When a cunsumer needs a particular type of object, he will scan through the object pool and get the required object.
problem here is when the cunsumer is scanning the object pool, how will he identify the different types of object,
since there will be lot of different type of objects in the pool?
I want to make my objects self explanatory, so that the cunsumer can identify them and consume them.
How do I achieve that?
Thanks in advance
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I don't think you're explaining yourself very well; I'm really unsure about what you're asking.
The code generated by XSD.exe, can you edit this? Can you change the names/re-arrange the namespaces to do this?
You could also look into attributes[^], which are a way of providing information about a class at the class level (rather than at the instance level). From what you're saying, I can only guess at attributes for the moment.
Could you explain further what you're trying to achieve?
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Hi All,
sorry for my bad english.
I need your help for reading a driver name available in the "Device management" of O.S.
Example, I install an USB driver associated with an internal COM PORT assigned from O.S., and I need to find this COM PORT associated at this driver.
I reading all com port of O.S., but what's the right one?
Thanks a lot for any suggestion.
Alex
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I don't know about getting the driver name, however using WMI class Win32_SerialPort one can obtain a lot of information, e.g. there are strings such as Caption, Description, DeviceID, Name. Not all of them are always present, however they should suffice to recognize the port you're looking for.
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Thanks Luc, I try this solution.
Alex
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You're welcome.
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First, sorry the subject title looks like an article name. 
I have a pdf document and has a button embedded using javascript. Is there a possible way i can develop a C Sharp application to click the button? Not me to click it
Wamuti: Any man can be an island, but islands to need water around them!
Edmund Burke: No one could make a greater mistake than he who did nothing because he could do only a little.
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I would have a look around at C# PDF libraries like PDFSharp[^] and iTextSharp[^]. There are ones out there that will allow you to print PDF documents.
Furthermore, I think trying to click the JavaScript-embedded button from C# is the wrong way to look at this - why would you try and run JavaScript inside a PDF that is open in memory in a C# application, especially when the JavaScript is probably dependent on Adobe Acrobat's particular implementation of JavaScript and its API? Why not just print it with your C# code?
Do you get what I mean? I thought I would just add that to explain why I didn't tell you how to click the button. I'm not trying to shoot you down, just shed some light on my thought process
EDIT: Brainwave! You probably don't even need a PDF library if all you're trying to do is print a PDF. Take a loot at the Adobe Reader's command line reference. Have a look at this post on Stack Overflow[^]. It shows two ways of printing with Adobe from the command line.
In C# you can achieve this by using System.Diagnostics.Process[^] class. This link shows you examples of starting a process.
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HELP, WHAT're the errors!!! ERROR - unsae
Error 1 Unsafe code may only appear if compiling with /unsafe C:\Visual Studio 2010\Projects\Unsafe\Unsafe\Program.cs 6 24 Unsafe
Error 2 Unsafe code may only appear if compiling with /unsafe C:\Visual Studio 2010\Projects\Unsafe\Unsafe\Program.cs 10 31 Unsafe
using System;
class Unsafe
{
unsafe static void SquarePtrParam(int *p)
{
*p *= *p;
}
unsafe public static void Main(string[] args)
{
int i = 5;
SquarePtrParam(&i);
Console.WriteLine(i);
}
}
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The error is saying you must use the /unsafe switch to compile code that contains the unsafe keyword. Go to the properties of the project, under the build tab and look for the checkbox "Allow unsafe code"
I know the language. I've read a book. - _Madmatt
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You already posted this as a question in the Q&A. Please don't cross-post.
I wasn't, now I am, then I won't be anymore.
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hey guys..i added a Unique constraint to a column in my sql table and if the user tries to add an existing data it gives error like that
"Violation of UNIQUE KEY constraint 'ukc_cekilis_no'. Cannot insert duplicate key in object 'dbo.NumaraBilgileri'."
it is ok..but i want to show an error message like that in my program..how i can check if the data already exist
vemedya.com
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You could catch that particular exception. You could use a stored procedure to do the insert that checks first and returns a value that tells you what happened. A third option would be to query before you do the insert, but that is inefficient as you are making two trips to the database instead of just one.
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T M Gray wrote: You could catch that particular exception.
Exceptions are for unexpected events not for normal processing.
I know the language. I've read a book. - _Madmatt
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If that were strictly true then there would be no throw method. There would also be no need for subclasses of Exception. If you know what type of Exception to expect then it isn't an unexpected event.
The answers I gave are factually correct. Your statement is a matter of philosophy or preference.
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T M Gray wrote: Your statement is a matter of philosophy or preference.
No, established best practices, architecture guidance and experience.
http://msdn.microsoft.com/en-us/library/seyhszts.aspx[^]
"Know when to set up a try/catch block. For example, you can programmatically check for a condition that is likely to occur without using exception handling. In other situations, using exception handling to catch an error condition is appropriate."
In this case the unique key violation is a known condition that may occur and can be tested for.
I know the language. I've read a book. - _Madmatt
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But do you know why it is bad practice? My point is that you shouldn't do something a certain way just because someone says so (even if that someone is Microsoft). Nothing in that article explains why you shouldn't use exceptions for program flow. If you had posted this[^] instead, that at least gives reasons related to performance.
There should be real reasons behind why you code a certain way. If the original poster is not strong in SQL and has no method of source control for database schema then using the stored procedure solution makes it less maintainable. That probably outweighs the performance impact of the Exception use in one method of a small application.
Blindly following a "best practice" without considering the specific situation is a bad idea. Consider this case[^] where it is a choice of one exception or 4 database roundtrips.
Avoid dogma in code.
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T M Gray wrote: But do you know why it is bad practice?
Do you?
Basically your arguments have no merit and are the ramblings of one uneducated in Software Engineering or Software Design principles. Further debate would solve no purpose against such an unprepared person.
I know the language. I've read a book. - _Madmatt
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So educate us. Tell us WHY. I laid out facts. You offered no solution to the original poster. You give no explanations. Try and contribute something useful rather than personal attacks.
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There's no hard and fast rules. But I agree with Mark. If a known condition can be tested for without relying on an exception, it's a best course of action. You cannot reliably know the behavior of a system as that system and its dependants rely on a failure mode, especially when any parts of the system get upgraded in the future. What may be an exception in one version may NOT be in the next.
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